Despite significant advancements in fluid dispensing devices and systems, many problems that have existed for decades related to such devices and systems remain unsolved. These problems exist in many different fluid dispensing applications, but have a particularly significant impact upon fluid dispensing devices and systems in the food and beverage industry as will be described below. Comestible fluid dispensers in this industry can be found for dispensing a wide variety of carbonated and non-carbonated pre-mixed and post-mixed drinks, including for example beer, soda, water, coffee, tea, and the like. Fluid dispensers in this industry are also commonly used for dispensing non-drink fluids such as condiments, food ingredients, etc. The term “comestible fluid” as used herein and in the appended claims refers to any type of food or drink intended to be consumed and which is found in a flowable form.
A majority of the long-standing problems in the comestible fluid dispensing art are found in dispensing applications for carbonated beverages. First, because the fluid being poured is carbonated and is therefore sensitive to pressure drops, conventional carbonated comestible fluid dispensers are generally slow, requiring several seconds to fill even an average size cup or glass. Second, when flow speeds are increased, the dispensed beverage often has an undesirably large foam head (which can overflow, spill, or otherwise create a mess) and is often flat due to the fast dispense. Some existing devices use hydrostatic pressure to push comestible fluid out of a holding tank located above the dispensing nozzle. One such device is disclosed in U.S. Pat. No. 5,603,363 issued to Nelson. Unfortunately, these devices do not provide for pressure control at the nozzle, and (at least partly for this reason) are limited in their ability to prevent foaming and loss of carbonation in the case of carbonated comestible fluids. The working potential of rack pressure in such devices is largely wasted in favor of hydrostatic pressure. By not maintaining rack pressure to the nozzles in these devices, carbonated comestible fluid inevitably loses its carbonation over time while waiting for subsequent dispenses. Also, like other existing beer dispensers, such devices cool and/or keep the comestible fluid cool by the relatively inefficient practice of cooling a reservoir or supply of comestible fluid.
Another problem of conventional comestible fluid beverage dispensers is related to the temperature at which the fluid is kept prior to dispense and at which the fluid is served. Some beverages are typically served cold but without ice, and therefore must be cooled or refrigerated prior to dispense. This requirement presents significant design limitations upon dispensers for dispensing such beverages. By way of example only, beer is usually served cold and must therefore be refrigerated or cooled prior to dispense. Conventional practice is to cool the beer in a refrigerated and insulated storage area. The process of refrigerating a beer storage area sometimes for an indefinite period of time prior to beer dispense is fairly inefficient and expensive. Such refrigeration also does not provide for quick temperature control or temperature change of the comestible fluid to be dispensed. Specifically, because the comestible fluid in storage is typically found in relatively large quantities, quick temperature change and adjustment by a user is not possible. Also, conventional refrigeration systems are not well suited for responsive control of comestible fluid temperature by automatic or manual control of the refrigeration system.
Unlike numerous other comestible fluids which do not necessarily need to be cooled (e.g., soft drinks, tea, lemonade, etc., which can be mixed with ice in a vessel after dispense) or at least do not require a cooling device or system for fluid lines running between a refrigerated fluid source and a nozzle, tap, or dispensing gun, beer is ideally kept cool up to the point of dispense. Therefore, many conventional dispensers are not suitable for dispensing beer. For example, beer located within fluid lines between a refrigerated fluid source and a nozzle, tap, or dispensing gun can become warm between dispenses. Warm beer in such fluid lines must be served warm, be mixed with cold beer following the warm beer in the fluid lines, or be flushed and discarded. These options are unacceptable as they call either for product waste or for serving product in a state that is less than desirable. In addition, because many comestible fluids are relatively quickly perishable, holding such fluids uncooled (such as in fluid lines running from a refrigerated fluid source to a nozzle, tap, or dispensing gun) for a length of time can cause the fluid to spoil, even fouling part or all of the dispensing system and requiring system flushing and cleaning.
Because many comestible fluids should be kept cool up to the point of dispense, the apparatus or elements necessary to achieve such cooling have significantly restricted conventional dispenser designs. Therefore, dispensers for highly perishable fluids such as beer are therefore typically non-movable taps connected via insulated or refrigerated lines to a refrigerated fluid source, while dispensers for less perishable fluids (and especially those that can be cooled by ice after dispense) can be hand-held and movable, connected to a source of refrigerated or non-refrigerated fluid by an unrefrigerated and uninsulated fluid line if desired.
A comestible fluid dispenser design issue related to the above problems is the ability to clean and sterilize the dispenser as needed. Like the problems described above, improperly cleaned dispenser systems can affect comestible fluid taste and smell and can even cause fresh comestible fluid to turn bad. Many potential dispenser system designs cannot be used due to the inability to properly clean and sterilize one or more internal areas of the dispenser system. Particularly where dispenser system designs call for the use of small components or for components having internal areas that are small, difficult to access, or cannot readily be cleaned by flushing, the advantages such designs could offer are compromised by cleaning issues.
The problems described above all have a significant impact upon dispensed comestible fluid quality and taste, but also have an impact upon an important issue in most dispenser applications: speed. Whether due to the inability to use well known devices for increasing fluid flow, due to the fact that carbonated fluids demand particular care in their manner of dispense, or due to dispenser design restrictions resulting from perishable fluids, conventional comestible fluid dispensers are invariably slow and inefficient.